Any summation of the defending champion Heat must begin with LeBron James. Even with the continued development of Kevin Durant and Tim Duncan’s resurgence, James is still the best player on the planet by what feels like a comfortable margin.

His scoring average is down two points, from 27.1 to 25.2, and he hasn’t been as dominant defensively. James has otherwise shown no signs of having spent the summer winning Olympic gold with Team USA, leading the league in Player Efficiency Rating for the sixth straight season while registering career bests in 3-point shooting and total rebound percentage.

A telling indication of the supporting cast the Heat have assembled, James’ usage percentage is at its lowest point since his second season. Chris Bosh, Dwyane Wade and newcomer Ray Allen all have PERs and per-36 scoring averages of at least 19.3, giving the Heat the most productive quartet in the NBA.

Their defense has been a puzzling shortcoming, however. It’s still too early to tell if the veteran Heat are merely pacing themselves, a la the 2000-01 Lakers, or have legitimately fallen off. Either way, their 26th-ranked defense has been a far cry from the units that finished 11th, sixth, fifth and fourth in Erik Spoelstra’s first four seasons.

That could provide the Spurs with a weakness to exploit with their surging offense. Otherwise, they’ll be hard-pressed to defend James, the ultimate matchup nightmare, with their top options, Kawhi Leonard and Stephen Jackson, sitting on the sideline.

* Even at 37, Allen has fit in seamlessly with his new team. The NBA’s all-time leader in 3-point baskets is shooting a career-best 52.9 percent from beyond the arc despite taking nearly four attempts per game — roughly twice as many as Kyle Korver when he shot 53.6 to set the league record in 2009-10.

* Bosh is also thriving, registering advanced numbers closer to his days in Toronto (24.6 PER, .229 win shares per 48 minutes) than his first two seasons with the Heat (18.9, .165; 19.4, .177). A big reason is his improved shooting, which includes a 67-percent clip on 4.7 attempts from 16-23 feet.

* The Heat are expected to be without one of their most important pieces in Battier. The veteran forward’s stats don’t grab the eye, but his ability to defend multiple positions, particularly power forwards, is a key to Miami’s so-called “position-less” basketball. That’s a blow to a team that was already struggling on defense.